1) Field of the Invention
The field of this invention relates to hand-held flashlights and more particularly to a flashlight which is sealed from the ambient in both a watertight and airtight manner.
2) Description of Prior Art
It has long been known that battery operated flashlights may create hydrogen gas during their operation. In most flashlights, the battery compartment is not sealed and therefore the hydrogen gas dissipates into the ambient and poses no hazard. It is well known that hydrogen gas is exceedingly explosive. It only takes a small amount of such gas and a slight spark to cause an explosion.
Some flashlights have battery compartments which are sealed and are intended to not only be airtight but also watertight so that the flashlights can be used under water. In these types of flashlights, the hydrogen gas that is generated cannot escape into the ambient. There are instances where the user of such a flashlight will grasp the flashlight, turn it on, and the flashlight will explode in the operator's hand. Such an explosion can cause injury to the operator.
It is desirable to include some type of device in conjunction with such a flashlight to insure that any hydrogen gas that may be generated by the batteries be either removed or rendered harmless. Within the prior art there has been incorporated a hydrogen absorbing pellet within the interior compartment of the flashlight. It is the function of that pellet to absorb any created hydrogen gas and thereby eliminate the hazard. However, the new flashlights have more powerful batteries. If a user abuses the flashlight by reversing polarity of the batteries or by mixing old and new batteries, these batteries have a much greater energy bleed-off. This means that there is more heat, more hydrogen gas, and therefore raised levels of internal pressure within the body of the flashlight. There is a possibility that the quantity of gas that is created within the internal compartment of the flashlight is too great to be absorbed by the pellet. Also the gas may be created so rapidly that complete absorption is not possible by the pellet.